DBSTalk.com uses a bulletin board app from http://www.forumrunner.net/ that I have heard is well received. I have no idea how much they charged for that. There is another option for DBR admins to install the Forumrunner software and then board members could purchase the app in the App Store for a couple bucks.
I just downloaded the DBSTalk app to check it out and it's definitely much nicer looking that the default mobile view in safari.
"Something in my vicinity is Carolina blue and this offends me." - HPR